# BCS-BEC crossover on the two-dimensional honeycomb lattice.

@article{Zhao2006BCSBECCO,
title={BCS-BEC crossover on the two-dimensional honeycomb lattice.},
author={Erhai Zhao and Arun Paramekanti},
journal={Physical review letters},
year={2006},
volume={97 23},
pages={
230404
}
}
• Published 2006
• Materials Science, Medicine, Physics
• Physical review letters
The attractive Hubbard model on the honeycomb lattice exhibits, at half filling, a quantum critical point between a semimetal with massless Dirac fermions and an s-wave superconductor (SC). We study the BCS-BEC crossover in this model away from half filling at zero temperature and show that the appropriately defined crossover line (in the interaction-density plane) passes through the quantum critical point at half filling. For a range of densities around half filling, the "underlying Fermi… Expand

#### Topics from this paper

Unconventional superconductivity on honeycomb lattice: Theory of Kekule order parameter
• Physics
• 2010
A spatially non-uniform superconducting phase is proposed as the electronic variational ground state for the attractive interactions between nearest neighbors on graphene's honeycomb lattice, closeExpand
Attractive Hubbard model on a honeycomb lattice: Quantum Monte Carlo study
We study the attractive fermionic Hubbard model on a honeycomb lattice using determinantal quantum Monte Carlo simulations. By increasing the interaction strength $U$ (relative to the hoppingExpand
Superfluid stiffness for the attractive Hubbard model on a honeycomb optical lattice
In addition to the conventional contribution that is directly controlled by the single-particle energy spectrum, the superfluid phase stiffness of a two-component Fermi gas has a geometricExpand
BCS-BEC crossover and superconductor-insulator transition in Hopf-linked Graphene layers: Hopfene
• Physics
• Materials Research Express
• 2019
We have proposed a topological carbon allotrope, named Hopfene, which has three-dimensional (3D) arrays of Hopf-links to bind 2D Graphene layers both horizontally and vertically without formingExpand
Semimetal-superfluid quantum phase transitions in 2D and 3D lattices with Dirac points
• Physics
• 2013
We study the superfluid properties of attractively interacting fermions hopping in a family of 2D and 3D lattices in the presence of synthetic gauge fields having \pi-flux per plaquette. The reasonExpand
BCS Theory of Time-Reversal-Symmetric Hofstadter-Hubbard Model.
• Medicine, Physics
• Physical review letters
• 2017
This work considers a two-component Fermi gas on a square optical lattice with opposite synthetic magnetic fields for the components, and explores the low-temperature phase diagrams of the model, displaying lobe structures that are reminiscent of the well-known Mott-insulator transitions of the Bose-Hubbard model. Expand
Superconductor-Insulator Transition and Fermi-Bose Crossovers
• Physics
• 2015
The direct transition from an insulator to a superconductor (SC) in Fermi systems is a problem of long-standing interest, which necessarily goes beyond the standard BCS paradigm of superconductivityExpand
Ultracold fermions in a graphene-type optical lattice
• Physics
• 2009
Some important features of the graphene physics can be reproduced by loading ultracold fermionic atoms in a two-dimensional optical lattice with honeycomb symmetry and we address here itsExpand
Disordered fermionic quantum critical points
• Physics
• Physical Review B
• 2018
We study the effect of quenched disorder on the semimetal-superconductor quantum phase transition in a model of two-dimensional Dirac semimetal with $N$ flavors of two-component Dirac fermions, usingExpand
Topological superconductors in correlated topological insulators on the honeycomb lattice
• Physics
• 2013
Abstract The paper realizes a topological superconductor (TSC) in correlated topological insulator – the interacting spinful Haldane model. The electrons on the Haldane model with on-site attractiveExpand

#### References

SHOWING 1-10 OF 31 REFERENCES
Semi-Metal-Insulator Transition of the Hubbard Model in the Honeycomb Lattice
• Physics
• 1992
Using quantum Monte Carlo and finite-size scaling for the Hubbard model, we find evidence of a zero-temperature transition between the nonmagnetic semi-metal and an antiferromagnetic insulator in theExpand
Mott-Hubbard transition and antiferromagnetism on the honeycomb lattice
• Physics
• 1996
AbstractThe Hubbard model is investigated for a halffilled honeycomb lattice, using a variational method. Two trial wave functions are introduced, the Gutzwiller wave function, well suited forExpand
BCS-BEC crossover of collective excitations in two-band superfluids
• Physics
• 2005
We use the functional integral approach to study low energy collective excitations in a continuum model of neutral two-band superfluids at T=0 for all couplings with a separable pairing interaction.Expand
Antiferromagnetism of the Hubbard Model on a Layered Honeycomb Lattice – Is MgB2 a Nearly-Antiferromagnetic Metal? –
As a model for the B 2 p z bands of MgB 2 , a half-filled Hubbard model on a honeycomb lattice is studied, and a possibility of an antiferromagnetism (AF) at the ground state is examined by MonteExpand
Interactions and phase transitions on graphene's honeycomb lattice.
• I. Herbut
• Physics, Medicine
• Physical review letters
• 2006
The Hubbard model in the large-N limit is shown to have a semimetal-antiferromagnetic insulator quantum critical point in the universality class of the Gross-Neveu model, and its consequences for various physical quantities are examined. Expand
BEC–BCS crossover in an optical lattice
• Physics
• 2006
We present the microscopic theory for the BEC-BCS crossover of an atomic Fermi gas in an optical lattice, showing that the Feshbach resonance underlying the crossover in principle induces strongExpand
BCS BEC crossover: From high temperature superconductors to ultracold superfluids
• Physics
• 2005
Abstract We review the BCS to Bose–Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction Ψ 0 . While thisExpand
Berezinskii-Kosterlitz-Thouless transition and BCS-Bose crossover in the two-dimensional attractive Hubbard model
We study the two-dimensional attractive Hubbard model using the mapping onto the half-filled repulsive Hubbard model in a uniform magnetic field coupled to the fermion spins. The low-energy effectiveExpand
Ground-state and finite-temperature signatures of quantum phase transitions in the half-filled Hubbard model on a honeycomb lattice
• Physics
• 2005
We investigate ground state and finite temperature properties of the half-filled Hubbard model on a honeycomb lattice using quantum Monte Carlo and series expansion techniques. Unlike the squareExpand
Critical temperature for the two-dimensional attractive Hubbard model
• Physics
• 2004
The critical temperature for the attractive Hubbard model on a square lattice is determined from the analysis of two independent quantities, the helicity modulus, $\rho_s$, and the pairingExpand